// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef GIN_DICTIONARY_H_
#define GIN_DICTIONARY_H_

#include "gin/converter.h"
#include "gin/gin_export.h"

namespace gin {

// Dictionary is useful when writing bindings for a function that either
// receives an arbitrary JavaScript object as an argument or returns an
// arbitrary JavaScript object as a result. For example, Dictionary is useful
// when you might use the |dictionary| type in WebIDL:
//
//   http://heycam.github.io/webidl/#idl-dictionaries
//
// WARNING: You cannot retain a Dictionary object in the heap. The underlying
//          storage for Dictionary is tied to the closest enclosing
//          v8::HandleScope. Generally speaking, you should store a Dictionary
//          on the stack.
//
class GIN_EXPORT Dictionary {
public:
    explicit Dictionary(v8::Isolate* isolate);
    Dictionary(v8::Isolate* isolate, v8::Local<v8::Object> object);
    ~Dictionary();

    static Dictionary CreateEmpty(v8::Isolate* isolate);

    template <typename T>
    bool Get(const std::string& key, T* out)
    {
        v8::Local<v8::Value> val;
        if (!object_->Get(isolate_->GetCurrentContext(), StringToV8(isolate_, key))
                 .ToLocal(&val)) {
            return false;
        }
        return ConvertFromV8(isolate_, val, out);
    }

    template <typename T>
    bool Set(const std::string& key, T val)
    {
        v8::Local<v8::Value> v8_value;
        if (!TryConvertToV8(isolate_, val, &v8_value))
            return false;
        v8::Maybe<bool> result = object_->Set(isolate_->GetCurrentContext(), StringToV8(isolate_, key),
            v8_value);
        return !result.IsNothing() && result.FromJust();
    }

    v8::Isolate* isolate() const { return isolate_; }

private:
    friend struct Converter<Dictionary>;

    // TODO(aa): Remove this. Instead, get via FromV8(), Set(), and Get().
    v8::Isolate* isolate_;
    v8::Local<v8::Object> object_;
};

template <>
struct GIN_EXPORT Converter<Dictionary> {
    static v8::Local<v8::Value> ToV8(v8::Isolate* isolate,
        Dictionary val);
    static bool FromV8(v8::Isolate* isolate,
        v8::Local<v8::Value> val,
        Dictionary* out);
};

} // namespace gin

#endif // GIN_DICTIONARY_H_
